YouTube is a video sharing website on which users can upload and share videos. Three former PayPal employees created YouTube in February 2005. In November 2006, YouTube, LLC was bought by Google Inc. for $1.65 billion, and is now operated as a subsidiary of Google.

The company is based in San Bruno, California, and uses Adobe Flash Video technology to display a wide variety of user-generated video content, including movie clips, TV clips, and music videos, as well as amateur content such as video blogging and short original videos. Most of the content on YouTube has been uploaded by individuals, although media corporations including CBS, the BBC, UMG and other organizations offer some of their material via the site, as part of the YouTube partnership program.

Unregistered users can watch the videos, while registered users are permitted to upload an unlimited number of videos. Videos that are considered to contain potentially offensive content are available only to registered users over the age of 18. The uploading of videos containing defamation, pornography, copyright violations, and material encouraging criminal conduct is prohibited by YouTube's terms of service. Accounts of registered users are called "channels".